Submarine-cable telegraphy



APril R. 'D. PARKER ET AL 1,708,974

SUBMARINE CABLE TELEIGRAPHY Filed Oct. 1925 INVENTORS 1 ZflZaI keI WJ WZUPermI/d ATTORNEY .20 v nometer coils which 'in turn will operate one or more mirrors to reflect one or more beams Patented Apr. 16, 1929.

UNITED f sTArEs PATENT orriclz.

nnnznmoivn n. PARKER AND WARNER L. OVEBTON, or BROOKLYN, NEW Yonx, As-

SIGNORSTO AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

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. I r K Application filed October 1925. Seria1 No. 61,325.

This invention relates to signalingsystem and more particularly-to receiving arrange.-

ments for systems over which the signals are transmitted by means of positive, negative and zero impulses, such, for example, as submarine cable telegraph systems.

When signals are transmitted by means of positive, negative and zero impulses over a circuit such, for example, as a submarine cable telegraph circuit, the signals, by the time they reach the receiving station, are usually very weak and special types of amplifying and recording arrangements have to be provided thereat for their reception.

It is one of the primary objects of thisin- 'vention to provide improved arrangements for amplifying and receiving, signals in sys: tems of the above mentioned types. In the arrangements. of the invention the incom ing signals will operate one or more-galvaof light upon photo-electric cells. An alternative arrangement might utilize refracting means instead of reflecting means for the purpose of directing the light beams. The circuits including these photo-electric cells, or other radio sensitive cells, will operate a receiving device to record the signals. With this type of arrangement it will .be seen that the primary moving element is a beam of light rather than an armature or other more weighty device. Accordingly, the weakness of the incoming currents will not be such a serious handicap to reception and signals much weaker than heretofore may readily be received. The arrangements of the invention also serve to improve the wave shape of the incoming signals and to eliminate the elfects of interfering-current. Other features and objects of the invention will appear more fully from the detailed descriptiomhereinafter given.

'The invention may now be more fully understood from the following description together with the accompanying drawing, in Figures 1, 2 and 3 of which the invention and a modificationthereof are illustrated. In Fig. 1 is shown a circuit diagram of one formof the invention, utilizing two galvanometers and two photo-electric cells, whilein Fig. 2 isshown an arrangement utilizing only one galvanometer and one photo-electric cell. Fig. 3 is a graphic illustration of certain of the principles of operation of the arrangements of Fig. 1.

also provided. A receiving circuit 5 is connected to the line 1. Connected in parallel with-the receiving circuit -5 are two vacuum tube amplifiers A and B In the output circuit of these amplifiers are the galvanometers 6 and 8. Mounted on each of these galvanometers are the mirrors 7 and 9 respec tively. Light sources 10 and 11 are provided to throw beams of light on these mirrors which will cause a reflected beam to be cast toward the photo-electriccells 12 and 13. In the circuits connected to these photo-electric cells are amplifiers A and B and the windings of a receiving relay 14. {This receiving relay 14 controls the contacts of circuits 15 which lead to a recording device such, for

example, as a siphon recorder. The amplifier A has a negative bias on its grid by reason of havingthe battery C in its input circuit connected with its negative terminal to thegrid. The amplifier B has a positive bias on its grid by reason of having a battery C in its input circuit connected with its positive terminal tothe grid.

Bynow referring to Fig. 3, it will be seen' that when the incoming signal is zero, the

plate current of amplifier A is given b the ordinate of p, and the plate current 0 am-v plifier B is given by the ordinate of 1*.

,When a positive impulse is received the plate current of A jumps from p to and back to p, while the plate'current 0' B,, being already-at a near saturation value 0*, cannot increase materially. When' a negative impulse is received the plate current of B jumps from 7' to s and back to 7, while the plate, current of A,, being already at a near zero value p, cannot decrease materially. Thus, we have amplifier'A responding to amplifiers responding to zero impulses.

In order to detect signals coming in at positive, impulses and amplifier'A respond- .ing to negative impulses, and neither of the high speeds, the mirror galvanometers 6, 7 and 8, 9 are placed in the output circuits of the amplifiers A and B,. Thesegalvanometersinay be of the moving coil type or of some other suitable type. Accordingly, a positive impulse coming in over the line 1 will be amplified by the amplifier A and will deflect the galvanometer 6. A negative impulse coming in over the line 1 will be amplified by the amplifier B and will cause the deflection of the galvanometer 8. A zero impulse obviously would leave the galvanometers in their normal positions. Galvanometer 6 is shown in its normal position. In this position the reflected beam of light from the source 10 will not touch the photoelectric cell 13. The galvanometer 8, however, is shown in its deflected osition due to an incoming impulse of negative polarity. This deflection of the galvanometer causes the light beam reflected from source 11 to fall on the cathode of the photo-electric cell 12. Accordingly, an incoming negative impulse will cause a light beam to fall on cell 12, an incoming positive impulse will cause a light beam to be reflected on cell 13, and zero impulses will cause no reflection of light on either of the cells. The reflection of the light beam on the sensitive element of the cell is to initiate or to increase the flow of electrons from the emitter to the receptor of the cell. These photo-electric currents thus generated by virtue of the positive signals in A and the negative signals in 13,, are then amplified by the amplifiers A and B respectively and transmitted to the windingsof the relay 14. The armature of relay 14 will move to one contact for a positive incoming signal and to the other contact for a negative incoming signal, and will stand in the air when no signal is being received. The movements of the armature accordingly may operate a siphonrecorder 012.. any other suitable recording device. y

In Fig. 2 is shown another arrangement of the invention in which only a single galvanometer 20 is included in the input circuit 5. This galvanometer-will be deflected in one direction by positiveincoming impulses and in the other direction by negative incoming impulses. Attached to the galvanometer 20 is the mirror 21, which will refleet the light beam from the source 22 to the \photo-electric cell 23. The photo-electric cell 23 has two central sensitized cathodes 24 and 25. A negative battery is con nected to each' of these cathodes, as shown; the positive terminals of these batteries being connected by conductor 27 to the inner surface of the bulb, which is coated with metal except for a small circular area through which the light enters. This inner surface therefore acts as an anode andcollects the electrons which are emitted from either cathode when it is illuminated, this phenomenon being known as a hoto-electrie effect. is a circuit comprising amplifiers such as A and B In the output circuits of these amplifiers are the windings of a relay 31, similar to the receiving relay 14 heretofore described. Controlled by this relay are conductors 32, leading to a recording device. When a zero impulse is transmitted, the galvanometer will not move and the reflected beam of light will fall directly between the two cathodes 24 and 25. A positive impulse coming in will cause the galvanometer to be deflected upwardly so as to cause the reflected beam of light to fall on the cathode 25. This will transmit current through the circuit of amplifier A and' actuate the relay 31 to cause the recording of a positive impulse. An incoming negative impulse will cause the galvanometer 20 to be deflected so as to cause the reflected light beam to fall on the cathode 24 to set up a current flow in the circuit of amplifier B to cause the relay 31to operate to record this negative impulse.

While this invention has been described and illustrated in certain forms it is capable of other and different forms and arrangements within the spirit and scope of the appended claims.

What is claimed is:

1. In a signaling system, a receiving circuit into which are transmitted signaling impulses of different character, a galvanometer device in said circuit giving difi'erent deflections in accordance with said differing incoming'signaling impulses, a light source, a reflector mounted on said galvanometer and moveable into different positions by said galvanometer deflections whereby the reflected beam of light from said source will assume different positions in accordance with said difiering incoming signaling impulses, a photo-electric" cell having a plurality of cathodes, and different signalin circuits controlled by each of said catho es, said photoelectric cell being so positioned with respect Associated with each 0 the cathodes to the reflected positions of said light beam that said different signaling circuits will be individually responsive to said different reflected positions of said light beam.

2. In a submarine cable telegraph system a receiving circuit into which are transmitted signals of ositive, ne ative and zero impulses, a ga vanometer eviee in said circuit, the moveable element of said galvanometer being deflected in one direction for positive impulses, in another direction for negative impulses, and remaining normal for zero impulses, a light source, a reflector operated by the moving element of said galvanometer whereby the reflected beam of light from said source may be caused to assume different positions in accordance with said incoming signaling impulses of different character, 5

photo-electric cell having a plurality of oath trolled by said individual amplifying cirodes, individual amplifying circuits concuits. 10 trolled by 'each of said cathodes, said cath- In testimony whereof, we have signed our odes being so positioned with respect to names to this specification this 7th day of the reflected positions of said light beam that October, 1925.

said individual amplifying circuits will be responsive to different reflected positions of RALZEMOND D. PARKER.

said light beam, and responsive means conn WARNER L. OVERTON. 

